Bayern and the Reds meet in the first leg at Anfield on February 19, with the return in Germany on March 13.
Neuer said: “I watched Liverpool's game against City – and you could see that they are not unbeatable. We have all seen that they are vulnerable — and I really don't think Liverpool want to play against Bayern.
“Liverpool are a classy team and have played a great season so far.
“They haven't conceded many goals and they are also very good on the counter-attack and strong at home. But I think our chances of winning are 50/50."
Bayern's squad have been in Qatar on a warm-weather training camp — and Neuer has promised that the plan is to have a strong second half to the season.
The Germany star said: “The aim is to prepare so that we are ready for the next stage of the season.
“It was not an easy first half because not everything went our way. We have to make amends and catch up."